mysql in 子查询 效率慢，对比

Posted 鴻飛

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 desc SELECT id,detail,groupId from hs_knowledge_point where groupId in (
    SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    UNION all
    SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
)
UNION ALL
SELECT id,detail,groupId from hs_knowledge_point_commit where groupId in (
    SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    UNION all
    SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
)
View Code
SELECT id,detail,groupId from hs_knowledge_point where groupId in (
    select groupId from (
        SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        UNION all
        SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    ) tmp
)
UNION ALL
SELECT id,detail,groupId from hs_knowledge_point_commit where groupId in (
    select groupId from (
        SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        UNION all
        SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    ) tmp
)
View Code

 

 

 

 

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